package programmercarl.动态规划.C21;

class Solution {
    public int combinationSum4(int[] nums, int target) {
        int[] dp = new int[target + 1];
        dp[0] = 1;
        for (int i = 0; i <= target; i++) {
            for (int j = 0; j < nums.length; j++) {
                //外层物品，内层背包是组合数；外层背包，内层物品是排列
                if (i >= nums[j]) {
                    dp[i] += dp[i - nums[j]];
                }
            }
        }
        return dp[target];
    }
}